Shadow Convertible L4-153 2.5L SOHC (1994)
A/C Signal: Description and Operation
PURPOSE
Powertrain Control Module (PCM) monitors engine load and A/C system pressure, and cycles the A/C compressor clutch accordingly.
OPERATION
When the A/C or defrost switch is ON, and the A/C high and low pressure switches are closed, the PCM receives an "A/C SELECTED SIGNAL".
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PCM engages A/C compressor clutch (by grounding clutch relay).
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PCM cycles compressor clutch depending on engine load and A/C system pressure.
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PCM maintains correct engine idle speed, through the Idle Air Control (IAC) Motor.